Question

IST is 5 and a 1/2hours ahead of GMT. Give reasons

Answer 1

Local time differs by 4 minutes per ° of longitude. India has a longitudinal span of approximately 30°. This puts the maximum local time difference between two places in India at 2 hours. If India had opted for multiple timezones, different parts of the country would have different local times at the same time. India doesn't need an extensive system with multiple timezones and the GMT+5:30 mark is most suitable because :

Most of the economically important cities lie close to the GMT+5:30 mark.Using the local time of the central location, the maximum difference in local time and National time would be 1 hour at any place in India. A difference of one hour would not be a serious issue.Using one timezone further avoid confusion over timings of trains, flights, etc when traveling domestically. Furthermore, radio/TV broadcasts need not have multiple timings, which further adds to confusion.